Texas Instruments TI-89 Manual Book page 451

Define progName(arg1Name, arg2Name, ...) = Prgm
block
EndPrgm
Creates
progName
subprogram, but cannot return a result using
. Can execute a block of multiple
Return
statements.
can be either a single statement or a
block
series of statements separated with the ":"
character.
and instructions (such as
) without restrictions.
For
Note: It is usually easier to author and edit a
program block in the Program Editor rather
than on the entry line.
DelFold
CATALOG
DelFold folderName1[, folderName2] [, folderName3] ...
Deletes user-defined folders with the names
folderName1
message is displayed if the folders contain
any variables.
Note: You cannot delete the
DelVar
CATALOG
DelVar var1[, var2] [, var3] ...
Deletes the specified variables from memory.
deSolve()
MATH/Calculus menu
deSolve(1stOr2ndOrderOde, independentVar,
dependentVar)
Returns an equation that explicitly or
implicitly specifies a general solution to the
1st- or 2nd-order ordinary differential
equation (ODE). In the ODE:
Use a prime symbol ( ' , press 2
denote the 1st derivative of the dependent
variable with respect to the independent
variable.
Use two prime symbols to denote the
corresponding second derivative.
The ' symbol is used for derivatives within
deSolve()
The general solution of a 1st-order equation
contains an arbitrary constant of the form
@k, where k is an integer suffix from 1
through 255. The suffix resets to 1 when you
use
ClrHome
solution of a 2nd-order equation contains two
such constants.
434 Appendix A: Functions and Instructions
as a program or
also can include expressions
block
If , Then ,
, etc. An error
folderName2,
folder.
main
a general solution
only. In other cases, use
or ƒ
. The
8: Clear Home
Define listinpt()=prgm:Local
n,i,str1,num:InputStr "Enter
name of list",str1:Input "No.
of elements",n:For
i,1,n,1:Input "element
"&string(i),num:
num! #str1[i]:EndFor:EndPrgm
¸
listinpt() ¸Enter name of list
Else , and
NewFold games ¸
(creates the folder
DelFold games ¸
(deletes the folder
2! a ¸
(a+2)^2 ¸
DelVar a ¸
(a+2)^2 ¸
Note: To type a prime symbol ( ' ), press
2
È.
deSolve(y''+2y'+y=x^2,x,y) ¸
right(ans(1))! temp ¸
) to
È
d(temp,x,2)+2ùd(temp,x)+tempìx^2
¸
DelVar temp ¸
d
.
( )
)
games
games )
(a + 2)ñ
y=(@1øx+@2)øe +xñ ì 4øx+6
ë x
(@1øx+@2)øe +xñ ì 4øx+6
ë x
Done
Done
Done
2
16
Done
0
Done